Hearing loss and loss of vision can be very harmful to the well-being and life of people who suffer from them. Usher syndrome is the name of a disease where people have both hearing loss and visual loss. In fact more than half of people who are deaf and blind have Usher syndrome. In this study we are trying to find the causes of all types of Usher syndrome and to learn more about how the eyes and ears work. Usher syndrome is caused by changes in our genes that lead to mistakes in the functioning of our eyes and ears.